Moving forward in putting predatory mite learning into practice:prey cue analyses and organizational upward cascades

Abstract: Generalist predatory mites such as Neoseiulus californicus and Amblyseius swirskiiare well able to learn prey in early life, profoundly and persistently enhancing the predators’foraging performance on this prey later in life. Enhanced foraging performance is evident inquicker prey recognition, shorter attack latencies, and higher predation rates, accompanied byhigher oviposition rates. Here we report on two ongoing major steps in putting this knowledgeinto practice. First, we determined that non-polar hexane extracts of Western flower thrips,Frankliniella occidentalis, are repellent to A. swirskii, whereas polar water extracts areattractive. Early life experience with water extracts alone was sufficient to enhance theforaging performance of the predators later in life. Second, using whole plants infested bythrips, we observed that early learning effects cascade up to the population and communitylevels and enhance the biocontrol efficacy of A. swirskii against F. occidentalis. Populationsfounded by thrips-experienced A. swirskii females were more efficacious in thrips control andplant damage reduction than populations founded by thrips-naïve predators. Both studiestogether emphasize the promising potential of translating early learning abilities into practiceand enhancing the biocontrol efficacy of predatory mites on a large scale.